\documentclass{article}

\usepackage{pgfplots}

\pgfplotsset{compat=1.14}

\begin{document}

\begin{tikzpicture}
	\begin{axis}[colormap name=viridis,colorbar]
	\addplot3[contour filled={number=, }] {x^2*y};
	\end{axis}
\end{tikzpicture}
\end{document}

